keeper of dragon magic secondary effect not working

[xxNOOBxxKILLAxx]

Any idea why you cant use keeper of dragon magics secondary effect to special summon a black luster soldier from the grave if you have a dragon master knight in your extra deck? The cards effect is as reads "if this card is normal or special summoned: you can discard 1 card; and add 1 polymerization normal spell card or fusion normal spell card from your deck. you can reveal 1 fusion monster in your extra deck; special summon 1 of the listed fusion materials whose name is specifically listed on that monster from your graveyard, in face down defense position. you can only use each effect of keeper of dragon magic once per turn. you cannot special summon monsters from your extra deck, except fusion monsters, the turn you activate either cards effects."

[[絶望] 𝔖𝔲𝔦𝔠𝔦𝔡𝔞𝔩_ℑ𝔡𝔬𝔩]

you have to properly summon ritual monster first before oyu can special them from the grave.

[katrinaninanina]

not true... it works just fine when summoning black luster solider using cosmo brain

[Tunnel Sharks Rule!!!]

Początkowo opublikowane przez katrinaninanina:

not true... it works just fine when summoning black luster solider using cosmo brain

Why did you necro bump this and who are you referring to